Enhancing lepton flavour violation in the supersymmetric inverse seesaw beyond the dipole contribution

In minimal supersymmetric models the Z-penguin usually provides sub-dominant contributions to charged lepton flavour violating observables. In this study, we consider the supersymmetric inverse seesaw in which the non-minimal particle content allows for dominant contributions of the Z-penguin to several lepton flavour violating observables. In particular, and due to the low-scale (TeV) seesaw, the penguin contribution to, for instance, Br(μ → 3e) and μ − e conversion in nuclei, allows to render some of these observables within future sensitivity reach. Moreover, we show that in this framework, the Z-penguin exhibits the same non-decoupling behaviour which had previously been identified in flavour violating Higgs decays in the Minimal Supersymmetric Standard Model.